Preventing Gestational Diabetes

Gestational diabetes is a fairly common complication of pregnancy. About 2 to 10 percent of pregnant women develop gestational diabetes. Because there are often no symptoms, women are routinely screened for the disorder during pregnancy.

Although gestational diabetes is potentially serious, there are ways to reduce your risk of developing it over the course of your pregnancy as well as manage the condition if you are diagnosed.

During pregnancy, the body’s need for insulin grows. Gestational diabetes mellitus (GDM) occurs when your body is not able to match this increased need and blood sugar rises to a point where it can pose considerable risks to mom and baby:

• Women with GDM are more likely to carry large babies, which may complicate delivery and raise the risk of a cesarean section. Shoulder dystocia, a rare emergency where the baby’s shoulders get stuck during delivery, is of particular concern.
• Babies may be born with hypoglycemia and may require treatment to raise their blood sugar levels.
• The risk of preeclampsia, a serious disorder that occurs in later pregnancy, is also increased in women with GDM.
• The risk of stillbirth rises in women with GDM.

Many women who develop gestational diabetes are no longer diabetic after they give birth. However, they are at an increased risk of developing type 2 diabetes later in life (as well as gestational diabetes in future pregnancies), so it’s important to tell your provider if you had gestational diabetes during pregnancy.

We don’t know why some women develop GDM; however, there are several known risk factors, including:

• Having GDM in a previous pregnancy
• Being obese
• Testing positive for glucose in your urine (this is routinely tested in the office)
• Having a family history of diabetes
• Being an older woman
• Being African-American, Hispanic, Native American, South or East Asian, or Pacific Islander.

If any of these risk factors apply to you, talk to your provider. He or she may initiate testing sooner.

Maintaining a healthy weight, eating a healthy diet, and exercising regularly may reduce your risk of GDM. A diet high in fiber and low in fat and refined sugars—like those found in white bread and pasta and in sugary foods like soda, candy, or pastries—may be particularly useful in staving off GDM. If you’re overweight, losing weight can also reduce your risk.

Check out these 10 Healthy Eating Rules.

If you smoke, it’s important to quit. Smoking is associated with numerous dangers to your baby, including placing you at greater risk of developing GDM.

In addition, some research indicates that breastfeeding reduces your future risk of developing gestational diabetes. Breastfeeding improves your ability to metabolize glucose and women who breastfeed tend to experience greater weight loss postpartum than those who don’t.

Between 24 and 28 weeks of pregnancy, your provider will order a glucose tolerance test:

• You will drink a specially formulated beverage, which contains 50 grams of glucose.
• Your blood will be drawn exactly one hour later.
• You do not need to be fasting when you come in, but once you drink the drink, you should not eat or drink anything (except for water, which we recommend) until after your blood draw. This includes avoiding gum and mints.

If your blood sugar level is normal, no other tests will be ordered.

If your blood sugar is elevated, you will return for the oral glucose tolerance test, also called GTT, which will determine whether you have gestational diabetes:

• You will arrive fasting (no food or drink except for water for 12 hours prior) and have your blood drawn.
• You will drink a beverage containing 100 grams of glucose.
• Your blood will be redrawn 1 hour later, again at 2 hours, and one more time at 3 hours.
• You cannot eat or drink anything other than the glucose drink and water throughout this time period.
• You must also stay in our office for the duration of the testing. This is to minimize movement as much as possible. If you are active, your body will process the glucose differently and it will affect the results of the test.

If you have two or more elevated blood sugar levels, it means you have gestational diabetes.

One of the best ways to combat GDM is through changes to your diet. In most cases, you’ll work with a nutritionist or dietician to develop a plan to reduce sugary foods and fat and increase fresh vegetables, fruit, and whole grains. Your provider may also recommend exercise to help control your blood glucose levels.

Your provider will also walk you through how to check your glucose levels using a home test kit or a continuous glucose monitor.

About 15 percent of women with gestational diabetes require insulin. If this is the case for you, you may be prescribed an oral medication or learn how to self-administer injections.

If you are a patient in our prenatal program in San Francisco, you will work closely with a specialized diabetes team based out of UCSF.

If you are diagnosed with GDM, you will likely have more frequent prenatal visits, particularly if you’re using insulin or your blood glucose levels are high. Your provider may also initiate what’s called nonstress testing during your third trimester. This testing monitors the health of your baby.

If your blood glucose levels are close to normal and you have no additional complications, it’s safe to deliver your baby between 39 and 40 weeks of gestation (40 weeks is full-term). If there are concerns about your baby’s health, you may be induced sooner.